test-and-publish.yml

name: Node.js Package

on:
  pull_request:
  push:
    branches:
      - main
      - master

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        node_version:
          - 12
          - 14
          - 16
    name: Test Node.js v${{matrix.node_version}}
    steps:
      - uses: actions/checkout@v2
      - uses: actions/setup-node@v2
        with:
          node-version: ${{matrix.node_version}}
      - run: npm ci
      - run: npm test

  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: actions/setup-node@v2
        with:
          node-version: ${{matrix.node_version}}
      - run: npm ci
      - run: npm run lint

  publish-npm:
    if: github.event_name == 'push'
    needs:
      - test
      - lint
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0
      - uses: actions/setup-node@v2
        with:
          node-version: 12
          registry-url: https://registry.npmjs.org/
      - name: Bump version (patch)
        run: |
          LATEST_TAG=$(git describe --tags --abbrev=0) || exit 1
          NEW_COMMITS=$(git rev-list --count "${LATEST_TAG}"..) || exit 1
          [ "${NEW_COMMITS}" -gt 0 ] || exit 0
          git config user.name 'github-actions[bot]'
          git config user.email '41898282+github-actions[bot]@users.noreply.github.com'
          npm ci
          npm version patch
          git push --follow-tags
      # `npm publish` must come after `git push` otherwise there is a race
      # condition: If two PRs are merged back-to-back then master/main will be
      # updated with the commits from the second PR before the first PR's
      # workflow has a chance to push the commit generated by `npm version
      # patch`. This causes the first PR's `git push` step to fail after the
      # package has already been published, which in turn will cause all future
      # workflow runs to fail because they will all attempt to use the same
      # already-used version number. By running `npm publish` after `git push`,
      # back-to-back merges will cause the first merge's workflow to fail but
      # the second's will succeed.
      - run: npm publish
        env:
          NODE_AUTH_TOKEN: ${{secrets.NPM_TOKEN}}